A federal judge has scheduled a mid-December hearing on a suit filed by the states of Kansas and Arizona over enforcement of citizenship requirements to vote.

The two states want to require new voters to prove they are United States citizens, even when they use a federal registration form.

Federal District Judge Eric Melgren in Wichita will hear the states’ arguments for a preliminary injunction to force the U.S. Election Assistance Commission to modify its national voter registration form.

The states want the form to include instructions for Kansas and Arizona residents to comply with state laws which require new voters to present a birth certificate, passport, or other proof of their U.S. citizenship.

The states are asking that the injunction take effect before the courts hear their suit, which claims the citizenship requirement is needed to prevent election fraud. Critics maintain the laws reduce voter turnout.

Arizona officials say if proof of citizenship is not required for state residents who register using the federal form, those voters will only be allowed to vote in federal elections.